Devices for dispensing and applying a makeup product such as mascara usually consist of a body forming a reservoir for the product and having at one open end, a neck part on which a stopper can be mounted, preferably by screwing, said stopper being provided with an applicator consisting of a shaft bearing a brush at its end.
Therefore, the applicator is immersed in the product contained in the reservoir when the device is in the closed position.
When it is desired to apply the product, the applicator is released by removing the plug with which it is integral, and making up the eyelashes by applying the product on the brush.
Throughout the makeup operation, which can be relatively lengthy, the product in the reservoir is exposed to the air through the open end of the reservoir.
The majority of makeup products, especially mascaras, tend to lose their cosmetic properties in contact with the air, and in particular tend to dry out.
After a certain number of uses, a portion of the product still in the reservoir becomes unusable.
In addition, the product is at risk of being contaminated by microorganisms as a result of its exposure to the air.